Preheat oven to 350°F.

Slice the bread horizontally through the middle, creating a top and bottom half. Set the top half aside, and set the bottom half on a lined baking sheet or inside a 9x13-inch casserole dish.

Layer on the ham, pepperoni, cheese, and salami, overlapping slices as needed to completely cover the bread. Scatter on roasted red pepper slices.

Whisk together the melted butter, Italian seasoning, and garlic powder. Brush half of the mixture onto the cut side of the top bread.

Place the top bread onto the sandwich, then brush the remaining butter over the top. (If you prefer, use all of the butter on top.)

Cover with foil and bake for 10 minutes, then remove foil and bake another 5-10 minutes, until cheese is melty and bread is golden brown. Slice and serve.